How to tell if it\'s ceramic or clay?

I recently inherited a Kamado cooker from my uncle who lives in South Florida. When he and I were discussing this cooker that he no longer used, he kept referring to it as a "Big Green Egg". He apparently purchased it from BGE when he lived in Atlanta over 20 years ago.

I went and picked it up last month and was surprised to see that it didn't look like the BGE's I knew (I live in Tucker and have been pining for a BGE for years now). My uncle insisted it's a BGE despite the fact that it's not even green.

I've done some online research and have discovered that BGE did import and sell some Kamado's in the late 70's through early 90's that weren't like their current high-temp ceramic BGE's they sell today. From what I've read, most of these were made of clay and can't withstand the higher temps that modern ceramics can.

Here's my question though, how do I know if it's made of ceramic or clay? I've seen photos of other Kamados that look almost identical to mine, but they all have a distinctive orange clay color where they weren't glazed. Mine has a reddish glaze, but the unglazed parts are more of a pale gray than an orangish clay color. Could it be that mine is actually made of ceramic and not clay?

Here's some photos that might help anyone willing to share some insight. Thanks in advance!